Production of hydrogen



Patented on. 24, 1933 v p I 1,931,492

UNITED ,srA'rss PATENT OFFICE PRODUCTION OF HYDROGEN No Drawing. Application February 6, 1931, 20113201). 514,070, and in Germany February 8 Claims. (01. 23-212) The present invention relates to the production The said mixtures of solid oxides have a better of hydrogen by splitting hydrocarbons by the efiect than solid oxides alone. Probably each action or heat. oxide promotes the action of the other oxide The main object or this invention is to proadmixed therewith so that they are mutual vide for a catalyst suitable for this reaction and activators. which has not the inconveniences encountered By oxidizable metals are meant those which with the catalysts hitherto in use. are oxidized under the conditions prevailing dur- It has already been proposed to split hydroing the heating up of the apparatus. carbons thermally into their components for the Also compounds of several solid oxides, such manufacture and production of hydrogen, and as aluminium silicate come into question as 65 to carry out the said reaction in the presence catalysts for the present process.

of heavy metals, such as iron, nickel or cobalt, The process according to the present invention and refractory materials such as fire clay. is carried out at high temperatures, preferably Frequently, in order to produce the high tembetween l000 and 1300 C. Any pressure, that peratures necessary for the splitting, the reaction is reduced, ordinary, or elevated pressures may 70 chamber, in some cases filled with a catalyst, be employed. Usually approximately atmosis heated up by the combustion of suitable gases, ph r p r i mp as for example a part of the hydrocarbons to The following examples will further illustrate be employed, the hydrocarbons then being led 'the nature of the present invention but the inthrough, the reaction chamber heated up again vention is not restricted to these examples. Thev 75 and so on. parts are by weight.

The employment or metallic catalysts, when Example 1 working in this manner, has many objections which are perhaps due to the fact that the said A mixture of 100 parts of aluminium hydr xi e heavy metals are oxidized during the heating and parts of zirconium oxide is brought into up and give their oiwgen wholly or pa uy t the form of cubes the edges of which are about the carbon of the hydrocarbons during the split- 30 millimeters in length y making into 8 paste ting reaction. The hydrogen obtained is con- With Suitable binding agent. as for a p taminated with carbon dioxide or carbon mon- Water, dilute organic acid, -P and 30 oxide, at least at. the start. Even the usually y 40 lit rs f h ca alyst thus obtained 1 employed refractory material s h a fire clay, are charged into a reaction vessel constructed of which, besides usually only having a very slight refractory material, as f example wp catalytic activity, and which are mainly employed d h at d to about 1250 C. by bu methane to provide a surface of contact, have a similar with air. 40 cubic meters of methane per hour 35 unfavorable efiect. Refractory materials, such are t led at a pressure of about 20 millimeters as fire clay always contain small a t of mercury through the apparatus until the temmetallic constituents or of constituents readily Pereture has f ll n t bout 1200 C. The rereduced t metals. action vessel is then heated again and so on. An I have now found that mixtures of solid oxides elllllent gas having p i t y the following 40 which are substantially free from oxidizable composition is obteinedl-f 5 metals, such as iron, nickel or cobalt, as such, p or in the form of compounds which are reducible Hydrogen 91.8 under the working conditions are very suitable Carbon monoxide 1.2 I as catalystsin the thermal splitting of hydro- Methane 0.2

45 carbons, in particular gaseous hydrocarbons of Nitrogen 6.8

the aliphatic series, as for example methane If the apparatus be charged with lumps of ethane or propane. For example, mixtures of chamotte, an emuent gas having appm ately two or more of the oxides of different metals 7 the following composition is obtained under the from the class consisting of aluminium, boron, Same conditions:

5 zirconium, silicon, cerium, thorium, or of the cent alkaline earth metals and the like may be em- Carbon dioxide 0.8 ployed. Gas mixtures containing hydrocarbons, Hydrogen 77.8 such as natural gas, cracking gas, coke oven Carbonmonoxide 3.0 gas or fractions of these gases, may be employed Methane 104 5 instead of the hydrocarbons themselves. Nitrogen ,0

Example 2 A catalyst is prepared in the warn-1w. described in Ex mple 1 from 100 parts of magnesium oxide, 1 pa of boric acid and 1 part of zirconium oxide. When methane is passed over this catalyst under the same conditions as set forth in or Mi w l a gas mixture having approximately the following composition is obtained:-

' Per cent Hydrogen 94 Carbon monoxide 0.6 Methane 0.4: Nitrogen 5.0 Example 3 Methane is passed under the conditions described in Example 1 over a catalyst prepared according to Example 1 from 100 parts of aluminium hydroxide, 20 parts of boric acid and 20 parts of silica. A gas having approximately the following composition is obtained:-

Per cent Hydrogen $9.4 Carbon monoxide lid Methane cc Nitrogen as It is not always possible to obtain a gas free from carbon monoxide since the methane employed which is obtained from technical-processes usually contains small amounts of carbon diomde and water which under the working conditions react with methane to form carbon ast ma the presence of a catalyst consisting of a mixture oil at lcmt two solid oxides which are substanti= ally tree trom substances comprising an oxidizable metal the oxide of which is reducible under the working conditions.

3. In the production of hydrogen by catalytic thermal splitting of methane, the step which comprises treating said methane at a high tem-' perature in the presence of a catalyst consisting of a mixture of at least two solid oxides which are substantially free from substances comprising a metal of the iron group.

4. In the production of hydrogen by catalytic thermal splitting of a gaseous hydrocarbon oi the methane series, the step which comprises treating said hydrocarbon at a high temperature in the presence of a catalyst consisting of a mixture of aluminium hydroxide and zirconium oxide.

5. In the production of hydrogen by catalytic splitting a gaseous hydrocarbon of the methane series, the step which comprises treating said hydrocarbon in the presence of a catalyst, consisting of a mixture prepared from about 100 parts of aluminium hydroxide and 60 parts of zirconium oxide, at a temperature between 1000 and 1300" 0.

6. In the production of hydrogen by catalytic splitting methane, the step which comprises treating said hydrocarbon in the presence of a catalyst, consisting of a mixture prepared from about parts of aluminium hydroxide and 60 parts of zirconium oxide, at a temperature be-- tween about l200 and 1250 C.

'7. In the production of hydrogen by catalytic splitting methane, the step which comprises passing said methane, at a. temperature between about 1200" and 1250 C., over a catalyst consisting of a mixture prepared from about 100 parts of magnesium oxide, 1 part of boric acid and 1 part of zirconium oxide.

8. In the production of hydrogen by catalytic splitting methane, the step which comprises passing said methane, at a temperature between about l200 and 1250" 0., over a catalyst consisting of a mixture prepared from about 100 parts 12;)

of aluminium hydromde, 20 parts of boric acid and 20 parts of silica.

minnow. 

